I. Field of the Invention
The invention relates to a seal that may in particular be fitted into an insulating glazing panel. This seal is particularly suitable for insulating glazing panels that are intended to be used in refrigerated cabinets, but the use of this seal is in no way restrictive and may be applied to any glazing panel having a housing intended to receive the seal of the invention.
II. Description of Related Art
Refrigerated cabinets are, for example, refrigerated display cases or chests whose insulating glazing panels constitute the glass fronts behind which products to be consumed are displayed. These products or foodstuffs, that have to be visible to the consumer, are perishable and therefore have to be kept at a suitable temperature, while preventing any bacteriological contamination.
The insulating glazing panels of these refrigerated cabinets are often joined end to end and the end glazing panels are generally attached to a side wall. However, a sufficient space must be provided between two glazing panels and/or a glazing panel and a side wall so as to allow a display case to be opened and closed in order to place or remove the products, or else to clean the display case, without any risk of striking the adjacent glazing panel or the side wall. Of course, it is paramount to provide a seal in this space so as to ensure thermal insulation between the refrigerated interior of the display case and the outside, to reduce thermal losses and to prevent any bacteriological contamination from outside the display cases of the products placed inside them.
Sealing is then achieved by seals fastened to the periphery of the glazing panels, each seal having a sealing lip that covers the lip of the seal of the adjacent glazing panel when the display cases are in the closed position, or else bears against the side wall. The seals are regularly put under stress as the display cases are being frequently opened and closed, and it is also preferable for them to be resistant to these rubbing forces by suitably fastening them to the glazing panel, while still being able to be easily removed for the purpose of replacing them.
Document U.S. Pat. No. 5,622,414 proposes a seal for these types of refrigerated cabinet.
The front of a refrigerated cabinet is formed from one or more insulating glazing panels, that are generally curved, comprising at least two glass panes separated from each other by an air or gas layer and held spaced apart by a spacer, together with sealing means designed to seal against water vapor and against water and/or other liquids between the inside and the outside of the glazing panel.
In that document, the spacer used on the lateral parts of the double-glazing panel consists of a hollow rigid strip that is open to the outside of the glazing panel and has a bottom facing the gas or air layer, side walls facing the internal faces of the glass panes and an opening on the opposite side from the bottom, giving access to the internal cavity of the strip at the edges of the glass panes. The free ends of the side walls toward the opening terminate in the form of a narrowed portion such as a constriction.
The sealing means of the insulating glazing panel consist of a first barrier impermeable to water vapor, such as a butyl seal placed between the side walls of the spacer and the internal faces of the glass panes, and a second barrier, impermeable to water and/or to other liquids, such as a polysulfide placed between the narrowed portion of the spacer and the internal faces of the glass panes.
The seal associated with this glazing panel includes a first portion that is held inserted in the cavity provided in the body of the spacer, and another portion placed on the outside of the cavity of the strip and projecting from insulating the glazing panel in order to cooperate with a seal for an adjacent insulating glazing panel.
More precisely, the seal of that document, which is obtained by extrusion, comprises a stem, a flat part extending the stem, a central rib located between the stem and the flat part, and flanges going from the stem obliquely toward the central rib. The stem and the central rib are made of a rigid plastic having a Shore A hardness of about 75 to 80 so as to ensure that they are inserted into the cavity of the spacer, in particular at the restriction, and to ensure that the seal is correctly positioned. The flanges and the flat part are made of a flexible plastic having a Shore A hardness of about 65 so as to ensure that they bend when the stem is forcibly inserted into the cavity, in particular at the restriction, and so as to ensure suitable flexibility for the flat part that is intended to cooperate with a flat part of a seal of an adjacent insulating glazing panel.
However, this seal does not seem to provide a completely satisfactory solution. This is because such a seal is necessarily associated with the spacer of the insulating glazing panel of the display case, this spacer having to have a specific shape, thereby requiring special spacers to be manufactured for these insulating glazing panels and resulting in additional production costs.
Moreover, if the central rib does not correctly close off the opening of the spacer, there is a possible risk of bacteriological contamination and proliferation in the cavity of the spacer, something which is inconceivable for this type of insulating glazing panel used in refrigerated cabinets intended for merchandizing food products.
Furthermore, the seal is made of at least two separate plastics—one rigid and the other more flexible—resulting in more complex manufacturing means than if the seal were to be obtained from a single material, and therefore not contributing to achieve as low as possible a manufacturing cost.
Finally, the sealing means of the insulating glazing panel, which in particular are made of polysulfide, are visible along the edge of the glazing panel, providing it with an unattractive appearance that may make customers feel that the display case is not clean.